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ATDome controls the Vera C. Rubin Observatory Auxiliary Telescope Dome.

The Auxiliary Telescope Dome is a 30 foot diameter Ash Dome with azimuth rotation and two shutter doors. The azimuth axis has no rotation limits. The top shutter door gives visibility from 30° elevation to zenith (90°), whereas the bottom shutter gives visibility from the horizon to 30° elevation.

User Guide

Start the ATDome CSC as follows:

Stop the CSC by sending it to the OFFLINE state.

See ATDome SAL communication interface for commands, events and telemetry.

For on-sky observing, send the ATDomeTrajectory CSC to the ENABLED state. Then ATDomeTrajectory will automatically command ATDome azimuth to follow the telescope. When you want to command ATDome azimuth manually, send ATDomeTrajectory to the DISABLED state to prevent it from commanding ATDome.

The moveAzimuth command is reported as done as soon as the command is received; use the azimuthState event to track when the move finishes. The door commands are reported done when the doors have finished moving.

New commands may be sent at any time. If a new door command arrives while the door is moving, the door immediately starts moving to the new position and the old door command is reported as superseded.


It is unlikely that a user will have to modify the default configuration for ATDome, as it only contains parameters for the connection to the low-level controller.

Configuration is defined by this schema.

Configuration files live in ts_config_attcs/ATDome.


The CSC includes a simulation mode. To run using simulation: --simulate

The simulated azimuth axis and shutter doors move at constant speed, with infinite acceleration.

Developer Guide

Version History